For a cool cat-fantasy I suggest Tad Williams' Tailchaser's Song. Simply a brilliant book, I first read it when I was about 12 and have read it more than ten times since.
Oh and the Otherland series of 4 (very thick!) books by Williams is also simply brilliant. Bit cyberpunkish and very adventerous(sp?) saga about a bunch of people who end up in a virtual cyberspace world trying to save the life of a lot of kids who went into a coma while plugged in into cyberspace.